|Publication number||US4754244 A|
|Application number||US 06/925,421|
|Publication date||Jun 28, 1988|
|Filing date||Oct 31, 1986|
|Priority date||Oct 31, 1986|
|Also published as||EP0266198A2, EP0266198A3|
|Publication number||06925421, 925421, US 4754244 A, US 4754244A, US-A-4754244, US4754244 A, US4754244A|
|Inventors||Anthony M. Pavio|
|Original Assignee||Texas Instruments Incorporated|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (8), Classifications (6), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to multiplier circuits and in particular to multiplier circuits that operate in the gigahertz band of frequencies and still more particular to a multiplier circuit utilizing distributed amplifier techniques.
Frequency multipliers are used in a variety of applications to extend the upper frequency limit of fixed or variable frequency oscillators. However, as the bandwidth of the multiplier approaches an octave, simple circuits become less useful because of the fundamental frequency energy which is present at the multiplier's output port. The problem is typically overcome by using a balanced structure to suppress a fundamental frequency such as transformers and microstrip baluns which also have bandwidth constraints.
A distributed balance frequency muliplier has a transmission line that is configured using lumped elements having connection points for inputting signals. Connected to each connection point is the output from a non-inverting amplifier which does not invert a signal applied thereto. A second transmission line is configured also using lumped element techniques and has connection points for receiving an inverted amplified signal whose odd harmonics are 180° to the non-inverting amplified signals. The signal that is to be amplified is carried to both the non-inverting and the inverting amplifier by a third transmission line that also uses lumped element distribution techniques to create a transmission line. The output of the first transmission line and the second transmission lines are tied together so that the odd harmonics due to the inverting amplification stages cancel and the even harmonics are additive, thereby achieving an effective multiplication of the input signal.
Each of the transmission lines is terminated into an impedance that is designed to match the characteristic impedance of the transmission line. Using field effect transistor circuits as the amplifier, the lumped elements are simplified because of the inherent capacitance associated with the gates of the field effect transistors. This enables the construction of the transmission line through the use of series connected inductors.
These and other objects and advantages of the invention may become more apparent from reading of the specification in combination with the figures in which:
FIG. 1 is a simplified block diagram of a radio receiver using a distributed balance frequency multiplier as a frequency doubler;
FIG. 2 is a simplified block diagram of a distributed balance frequency multiplier according to the invention;
FIG. 3 is a schematic diagram of a distributed balance frequency multiplier according to the invention;
FIG. 4 is a diagram of a field effect transistor illustrating the internal capacitance; and
In FIG. 1, to which reference should now be made, there is shown a radio receiver 10 that is designed to operate in the frequency band ranging from b 5 to 20 gigahertz. The radio receiver operates by receiving radio signals via an antenna 1 and applying the received radio signals to a mixer 3 which down converts the received radio signals to the IF range and applies the IF range signals it to an IF processor 5 which processes the applied IF signals providing as an output, baseband data. The mixer 3 mixes the received radio signal with a local oscillator signal that is provided by a circuit that includes a local oscillator 7, a double pole double throw switch 9 and a doubler 11.
When the double pole double throw switch 9 is in position A, the output from the local oscillator 7 provides a local oscillator signal to the mixer 3 that can be varied in the range between 5 and 10 gigahertz. However, for receiving radio signals having a carrier frequency greater than 10 gigahertz, then the doubler 11 must be used and this is accomplished by placing the double pole double throw switch 9 to position B. The local oscillator 7 then provides a signal that ranges in the 5 to 10 gigahertz range to the double 11 which doubles the signal and provides a local oscillator signal to the mixer 3 that ranges between 10 and 20 gigahertz, thus, effectively extending the band of operation of the radio receiver 10. The doubler 11 is an embodiment of a distributed multiplier according to the invention.
In the embodiment of FIG. 2, to which reference should now be made, the frequency doubler 11 includes a first transmission line 25. The transmission line 25 is a series connection of lumped elements 13. As in the case of most distributed element networks such as that illustrated in FIG. 2, each lumped element includes a combination of an inductor 17 and capacitor 15. The transmission line is terminated by an impedance 23A which has an impedance equal to the characteristic impedance of the transmission line at the band of frequency to which the doubler 11 is to be operated. This impedance is defined as Zo. A second transmission line N27 is again a series connection of lumped elements 13 that is terminated by impedance 23B having the characteristic impedance Zo of the second transmission line. Connected to receive the input from the local oscillator 7 is a third transmission line 29 that also is configured using distributed lumped element techniques and includes a plurality of series connected lumped elements 13 terminated by a resistance 23C having the characteristic impedance Zo of the third transmission line. Between each pair of lumped elements 13 of the first transmission line 25, second transmission line 27, and third transmission line 29 is a node. At node 35, the local oscillator signal present there is applied to an inverting amplifier 21 and a non-inverting amplifier 19.
Non-inverting amplifier 19 is connected to node 30 of the first transmission line 25 and inverting amplifier 21 is connected to node 41 of the second transmission line 27. At each node, because the system is a distributed lumped element network, the characteristic impedance in each direction from each node is equal to Zo in the preferred embodiment. Therefore, at node 30 an non-inverting amplified signal is applied to the first transmission line 25 and at node 41 an inverted amplified signal of the node that is present at 35 is applied thereto.
Because the circuit just described is repeated in a similar fashion at each set of nodes, then the circuits can be identified as a series connection of stages shown by dotted blocks as a first stage 61, a second stage 63 and a third stage 65. The second stage input to the first transmission line 25 is at node 31 and the third stage input is at node 33. In a similar fashion, the inverted input is at node 42 of the transmission line 27 for the second stage and the third stage is at node 43. Node 37 provides the input signal to the non-inverting amplifier 19 of the second stage 63 and the inverting amplifier 21 also of the second stage 63, whereas node 39 provides the input signal to the non-inverting amplifier 19 and the inverting amplifier 21 of the third stage 65. At node 46, under ideal conditions where the gain of the amplifier 19 is equal to the gain of the amplifier 21, the signals that are present on the first transmission line 25 and the signals that are present on the second transmission line 27 are vectorally combined. Because the odd harmonics of the signal that is applied to the amplifiers 21 have been phase shifted 180° and the even harmonics have been phase shifted 360°, then at node 46, the odd harmonics cancelled and the even harmonics add to provide a multiplication of frequency of the output from the oscillator 7. The output transmission line 14 for optimum operation has a characteristic frequency to 2Zo as is illustrated by block 44.
FIG. 3 is a schematic diagram of a distributed balance frequency multiplier according to the invention in which each transmission line 25, 27 includes a series connection of inductors 17 and 17'. In the preferred embodiment, the circuit of FIG. 3 is implemented as a single substrate using GaAs technology. The non-inverting amplifier 19 is a common gate field effect transistor circuit using a field effect transistor 78 whereas the inverting amplifier 21 is a common source field effect transistor using a second field effect transistor 78. The embodiment shown in FIG. 3 is a multi stage circuit in which the number of stages is determined by the desired gain of the output and the bandwidth. The more stages that are used, the narrower the bandwidth, but the higher the gain. Therefore, these elements are considered when designing a multiplier according to the invention.
The capacitance elements for the embodiment is FIG. 3 is provided by the internal capacitance of the field effect transistor 78 which is shown in FIG. 4. Capacitors 75, 76 and 77 are the gate capacitance for the gate of the field effect transistor 78 and capacitance 79 is the drain to source capacitance which comes into play in the common source circuit 21 shown in FIG. 3.
The size of the inductors are selected based on the impedance presented by the internal capacitance of the gates of the field effect transistor 78 and the inductors 17 and 17' to provide an impedance of Zo in each direction as is indicated by arrows 99 at each node.
For the embodiment of FIG. 3 manufactured on GaAs the following characteristics were achieved:
Inductor 17 or (17'+17')≅0.5 nano Henry
Gate Capacitance≅0.27 pico farads
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4486719 *||Jul 1, 1982||Dec 4, 1984||Raytheon Company||Distributed amplifier|
|US4531105 *||Dec 23, 1982||Jul 23, 1985||Rca Corporation||Frequency multiplier circuit for producing isolated odd and even harmonics|
|US4660006 *||Apr 15, 1985||Apr 21, 1987||Raytheon Company||Radio frequency multiplier producing an even harmonic output|
|US4668920 *||Apr 14, 1986||May 26, 1987||Tektronix, Inc.||Power divider/combiner circuit|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6476692 *||Jul 13, 2001||Nov 5, 2002||Fujitsu Quantum Devices Limited||Distributed balanced frequency multiplier|
|US6529051||Feb 27, 2001||Mar 4, 2003||Fujitsu Quantum Devices Limited||Frequency multiplier without spurious oscillation|
|US7132890 *||Aug 7, 2003||Nov 7, 2006||Agilent Technologies, Inc.||System and method for providing distributed amplification|
|US7138870 *||Aug 7, 2003||Nov 21, 2006||Agilent Technologies||System and method for providing a lossless and dispersion-free transmission line|
|US8451033||Dec 14, 2010||May 28, 2013||Taiwan Semiconductor Manufacturing Co., Ltd.||Millimeter-wave wideband frequency doubler|
|US20050030102 *||Aug 7, 2003||Feb 10, 2005||Landolt Oliver D.||System and method for providing a lossless and dispersion-free transmission line|
|US20050030103 *||Aug 7, 2003||Feb 10, 2005||Landolt Oliver D.||System and method for providing distributed amplification|
|EP1154563A2 *||Feb 23, 2001||Nov 14, 2001||Fujitsu Quantum Devices Limited||Frequency multiplier without spurious oscillation|
|U.S. Classification||333/218, 330/286, 363/159|
|Oct 31, 1986||AS||Assignment|
Owner name: TEXAS INSTRUMENTS INCORPORATED, 13500 NORTH CENTRA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PAVIO, ANTHONY M.;REEL/FRAME:004640/0437
Effective date: 19861031
Owner name: TEXAS INSTRUMENTS INCORPORATED,TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PAVIO, ANTHONY M.;REEL/FRAME:004640/0437
Effective date: 19861031
|Sep 20, 1991||FPAY||Fee payment|
Year of fee payment: 4
|Sep 29, 1995||FPAY||Fee payment|
Year of fee payment: 8
|Mar 3, 1999||AS||Assignment|
Owner name: RAYTHEON COMPANY, MASSACHUSETTS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TEXAS INSTRUMENTS INCORPORATED;REEL/FRAME:009764/0360
Effective date: 19990212
|Nov 12, 1999||FPAY||Fee payment|
Year of fee payment: 12